The invention relates to welding backup systems for purge purposes and as especially advantageous for welding construction of creases with tanks and the like.
When for example and without limitation stainless steel is being welded, it is preferred it be done so in an atmosphere purged of oxygen. A suitable purging gas is nitrogen, for example. Some welding practices include inserting an entire assembly of the article-to-be welded in an oxygen-purged room or, on a reduced scale, glass chamber or case. What is needed is an improvement to flood a highly-pinpointed work area only with a purge gas in an otherwise breathable atmosphere for the workers.
A number of additional features and objects will be apparent in connection with the following discussion of the preferred embodiments and examples with reference to the drawings.